Mobile WiMAX standards define an idle mode during which a mobile station (MS) may power down components in an effort to conserve power. In the idle mode, the MS powers up components to monitor for page messages in recurring MS Paging Listening (“listening”) intervals, while powering down components in MS Paging Unavailable (“sleep”) intervals.
In a mobile WiMAX network, each WiMAX frame has a 24-bit frame number that increments every frame until the maximum is reached before restarting from zero. This frame number can be used to decide when a Base Station (BS) should send a BS Broadcast Paging (MOB_PAG-ADV) message, at some Paging_Offset within a periodic Paging_Cycle. To synchronize with the paging cycle of a BS, the MS may start to listen for the MOB_PAG-ADV message from frame number N when:N mod Paging_Cycle=Paging_Offset  (1)
Each MOB_PAG-ADV message may contain one or more 24-bit MAC Address Hash (i.e., generated as a hashed value of the full 48-bit MAC address of a targeted MS). When an MS sees a MOB_PAG-ADV message containing a match with its 24-bit MAC Address Hash (generated with its own 48-bit MAC address), the MS knows that this MOB_PAG-ADV message is destined for itself.
Unfortunately, an MS needs to stay awake for the whole paging listening interval to determine if a MOB_PAG-ADV message contains a match with its MAC address hash. Per WiMAX standards, a paging listening interval L can be as long as 5 frames, which may result in a substantial waste in terms of power consumption in the event that the MS is not paged.